Fucking knew it, the author would pull something to prolong the complicated nature of these two's relationship. This new source of dramatic tension is interesting since if it is true then the ex-husband might as well come into the picture to further muddle things up, and if she was lying, then you know she's the type who'd say or do anything just to save face, thus things would be an even worse uphill battle for MC-san. The stuff others have mentioned about her possibly being his daughter would also be big if true.